Insecure attachment can show up in many ways. We very likely learnt that others don't care about our emotional needs, or cannot fulfill them (emotionally unstable/unavaiable caregivers, or physically/emotionally absent ones, is often where it all started, making us feel wrong and unsafe, insecure). So yes, trying to heal this is gonna be a long walk through unmet needs from our past.
When you don't feel secure, you cannot express your emotions without fear, cause you need approval from others. Try writing first, write down how you feel and what you'd need to have those feeling (and needs) met. Don't run away from your emotions. Know them by feeling them and taking some time to write things down.
Feeling unsafe may have you need for constant reassurance: be clear about what could help you when it comes to texts, calls and everything around those. Remind yourself that the other person has needs as well and find a compromise that can satisfy both parties, so to avoid you to stress and overthink by guessing things that aren't even real. Try to heal yourself by getting more in touch with yourself (needs and fears) when you're alone. You can never be really alone (nor entirely lonely), when you're with you as a friend would.
If you fear being abandoned you may end up pushing others away, to avoid being hurt if they do that to you. Try to be more vulnerable: explain yourself first and then to the other party, why you feel overwhelmed or scared, for example by arguments, and how they can trigger you into ignoring the other person (usually relates to childhood traumas). You may also feel jealous, or left alone, fearing of being not enough and therefore abandoned. Check in with the reasons behind this: don't let thoughts take over, sometimes we get triggered by our past. You need to find objective reasons, and even more, what are the needs that are not being met in your relationship. Talk those out.
If you try to be overly independent or fear being rejected for having needs, you may have many unmet needs from your past. Especially when you were a child, when you probably had to care about yourself on your own (even for just your emotions) or were in charge for keeping others happy and started avoiding your own needs. Be open about your wishes, desires, and about how having support could be of help to you and for the relationship. Don't be scared to ask for help: keep doing everything alone may have you end up into passive-aggressive mood, cause others often don't understand we need help if we don't ask. They may even think you like doing what you do, even if it's chores and it's something you hate or don't feel like doing. Tell them that. Healthy relationships are based on mutual collaboration and help. You don't have to do everything alone, not anymore.
But most of all, be open to the fact that things can change, and that you can find people that support you and help you, and appreciate you the way you are and won't leave you, cause you're worth of everything. Love and affection in particular.