Tawba means one if regretful and has made a resolve to never repeat the sin. If the action can be compensated for (if for example the sin was one did not fast which can be compensated for by doing qadha and the necessary kaffara if it applies and so on and so forth).
Other sins don't have a compensation and just by resolving not to repeat and being regretful of it, Allah forgives.
In regards to the waswas, it would be advisable to refer to a counselor who can find the root of it and get rid of it so you can reach peace.
As for closeness to Allah and Ahlul Bait, the best way is to stop sinning and act on wajibat however waswas is something that will interfere in this and must first be cured.